Answers for "how to update a column in mysql"

update all rows mysql

UPDATE tableName SET columnName = yourValue;
#to update multiple columns:
UPDATE tableName SET column1 = value1, column2 = value2; #and so on

change column in mysql

#Alter is used
#alter table TableName change CurrentColumnName NewColumnName Specification(size);
alter table TableName change name firstname varchar(30);

update column mysql with alter

ALTER TABLE table_name
  MODIFY column_name column_definition
    [ FIRST | AFTER column_name ];